The present invention relates to a traffic management system for managing in a road network the vehicle traffic formed on a physical layer by a plurality of vehicles.
In particular, the present invention addresses the problem of how an effective traffic management system can be devised, which can be adapted, changed and extended easily to provide different types of traffic management depending on the prevailing traffic conditions in the physical layer in order to provide different types of intelligence for an effective traffic management. The different types of traffic management concern the traffic management aspect of merely effectively monitoring the existing traffic as well as the traffic management aspect of effectively controlling the traffic. The different types of traffic management include for example different types of effective settings of traffic control signs, various different route-planings by not only considering traffic jams and congestions but also road charging, the gathering of statistical data from existing traffic, the prevention of dangerous or generally unwanted traffic situations by changing traffic signs in case of dangerous traffic situations, as well as the achieving of different traffic situations with different traffic control mechanisms.
Thus, the traffic management system of the invention should generally be flexible in its control and in its extension and adaption functions.
With the ever increasing demands to growing mobility, the automobile industry has developed the vehicular technology to such a degree that now a range of products for various purposes and missions are available and an adequate cost-benefit balance can be provided for every application. On the other hand, the growing demand to mobility has caused the need for the public authorities to extend the old network of roads and highways to cope with the ever increasing traffic.
However, the expansion of the network and the related infrastructure has been notably smaller than the increase of the number of vehicles. That is, the existing road networks cannot cope with the ever increasing traffic and this unbalance causes traffic situations with congestions and accidents. Other consequences are an increased fuel consumption, general waste of time, the environmental pollution, noise, stress and other discomfort for humans. Apart from not very effective counter measures to stop the growth of the traffic, such as increasing fuel cost and higher taxation, there are no effective counter measures with which the gap between the mobility demand and the necessary infra-structural means can be bridged which leads to higher transportation costs, waste of fuel and time, environmental problems as well as a lower safety level.
These circumstances have resulted in a high demand for effective traffic control measures to avoid a collapse of a complete transportation system. Therefore, it is now generally accepted that a wide range of more global and integrated measures have to be identified and implemented together with a systematic approach. In particular, the demands to a new traffic control system are to balance the demand and offer within the whole transport system, i.e. to manage the transport resources (roads, traffic signs etc., traffic flow control) to be optimally adapted to the traffic situations and demands (i.e. number of vehicles, type of vehicles, desired destination etc.).
At present several new approaches for more effective traffic (congestion) control systems are tested, in particular in the Netherlands. However, most of the traffic control systems existing today are of a rather static nature. Only some of them use changeable traffic signs depending on the time of day or the actual traffic situation, e.g. a variable speed limit on a motorway depending on the congestion condition. Thus, only a few traffic signs (such as parking permission, speed limit, use of one or two lanes on a road) may have a different meaning depending on the time of day or the day of the month and they are not controlled in an integrated manner, i.e. they do not take into account a traffic situation which exists elsewhere (away from the road section where e.g. the particular variable speed limit is arranged) but which may also have an influence on the road section considered.
For monitoring purposes certain highways are on a limited scale equipped with sensors, which measure the traffic flow and provide information in the traffic loads or bad weather conditions in order to change some traffic signs mounted above the highway to indicate dangerous situations. However, this change of warning signs like bad weather conditions, accident and congestion only change the traffic signs on the highways in a very limited scale, namely on a rather local scale rather than being able to more globally control the complete traffic flow for example in an integrated manner in a whole area of for example one or two local areas, e.g. a complete city.
Conventional Traffic Management Systems
On a rather limited scale traffic management systems are already available or are being currently tested. In one system called the xe2x80x9cIntelligente Snelheidsadaptorxe2x80x9d (Intelligent Speed Control) tested in the Netherlands, a vehicle is equipped with a traffic information unit and a speed broadcasting system of the traffic information system receives some traffic information from a traffic information system and broadcasts the appropriate speed in each area of a road network. This system is very specifically directed to speed control in a limited area and no provisions are made for including further control of traffic situations on a global basis.
In another systems called the xe2x80x9cRekening-Rijdenxe2x80x9d (Tag Billing System) some sensors are arranged at certain road points to sense the passing of a vehicle with an identification tag. This system only performs a monitoring of the traffic and allows to charge persons who have used a road more accurately.
On the other hand, route-planners (mostly employed in vehicle navigation systems) are fairly static and do not take into account road-blocks, congestions, i.e. the actual traffic situation. Here, the traffic management system merely employs on-board-computers, which inform the driver about the shortest route to the corresponding destination.
Mobile radio communication systems such as GSM (Global System of Mobile Communication), GPRS (General Packet Routing System) and UMTS (Universal Mobile Telephone System) are also partially used in traffic management systems. A GPS (Global Positioning System) system is used to determine the location and speed of a vehicle and a central control office is informed when a certain amount of vehicles is lower than usual. A SMS message (Short Message System) can be broadcasted to all mobile stations in a corresponding region to advise them to select another route. The other routes are manually selected and there is as such no actual traffic flow control by using particular control methodologies.
As may be appreciated from the above description, there are various traffic management systems, which perform some kind of monitoring and limited control of the vehicle traffic, however, the systems are set up in such a specific manner that even their integration or combination is difficult, i.e. each system is developed independently and has thus a very rigid construction geared to a specific purpose such that an extension or modification is not easily possible. Thus, if there arise traffic situations in the future with which the static conventional traffic management systems cannot cope, then it is required to develop a completely new system. The reason for this is that the conventional traffic management systems where only designed very specifically for a single specific test purpose, i.e. monitoring or a speed indication, such that a further extension and modification was never contemplated for these test systems.
As explained above, conventional traffic management systems are geared so specifically to a certain control purpose or monitoring purpose such that the system cannot easily be extended, modified or adapted to more complicated traffic situations or more complicated control if the traffic situation changes, in particular if the traffic situation changes on a global bases. That is, in the conventional systems the whole traffic management system operates on a single layer in which the collecting of information about traffic flow, the control as well as the communication of various types of traffic messages are exchanged. Thus, every time a new function is to be added, this will mean a complete redesign of the system, which is extremely tedious, user-unfriendly and cost-intensive.
Therefore, the object of the present invention is the provision of
a traffic management system which can easily be modified, extended and adapted to new traffic situations and traffic control scenarios.
This object is solved by a traffic management system comprising a layer structure including at least a traffic signalling layer including a plurality of traffic signalling units for monitoring and/or controlling the vehicle traffic and a traffic signalling layer information exchange interface adapted to output traffic signalling information about the vehicle traffic on the physical layer; to receive traffic control information for controlling the vehicle traffic; and to output traffic guidance information to the vehicles on the physical layer; and a traffic control layer including a packet switched control network, in which the packet traffic is controlled with a predetermined packet control method to correspond to or simulate the vehicle traffic on the physical layer, including a traffic control layer information exchange interface adapted to receive traffic signalling information about the vehicle traffic on the physical layer; to output traffic control information for controlling the vehicle traffic; to output packet signalling information about the packet traffic; and to receive packet control information for controlling the packet traffic in the packet switched control network.
The traffic management system in accordance with the invention is a layered structure, in which at least two different layers are incorporated, to which specific traffic management functions are assigned. The exchange of messages between these layers is standardized such that a complete layer can be exchanged with a new layer without changing functions in other layers. Thus, one layer can be modified according to need without the requirement of redesigning the whole system.
Advantageous Embodiments
Further advantageous embodiments and improvements of the invention are listed in the dependent claims. Hereinafter, the invention will be described with reference to its advantageous embodiments and with respect to what is currently considered by the inventors to be the best mode of the invention.
Furthermore, it should be noted that the invention can be modified and varied in many respects on the basis of the teachings contained herein. For example, the invention may comprise embodiments, which are a result of combining features and steps which have been separately described and listed in the claims, drawings and in the description.